Vulcanized rubber or thermoplastic rubber breathability test

Measuring the air permeability of rubber is important in evaluating the compounds used in the manufacture of inner tubes, tubeless tire liners, hoses, balloons and other air containers, seals and films. This measurement is of theoretical interest when studying the diffusion and dissolution properties of gases in relation to polymer structure.
The air permeability test of vulcanized rubber or thermoplastic rubber uses the differential pressure method or the isobaric method to determine the air permeability of vulcanized rubber or thermoplastic rubber, including the measurement of gas permeability, gas permeability coefficient, gas diffusion coefficient and gas solubility coefficient.
Zhongke Testing Reliability Experiment Center has the ability to test the reliability performance of various vulcanized rubbers or thermoplastic rubbers, and provides professional breathability testing services for vulcanized rubbers or thermoplastic rubbers.

Vulcanized rubber: flat vulcanizing machine vulcanizing type, vulcanizing tank vulcanizing type, continuous vulcanizing type, special vulcanizing type, etc.
Thermoplastic rubber: polystyrene, polyurethane, polyolefin, polyester, ethylene-vinyl acetate copolymer, ethylene-acrylate copolymer, polyethylene-butyl rubber joint copolymer, etc.

1. Pressure difference method: Use a sample to divide the breathable test chamber into high-pressure side and low-pressure side. Inject the test gas into the high-pressure side and ensure that a constant pressure difference (adjustable) is formed on both sides of the sample; the gas permeates and diffuses from the high-pressure side to the low-pressure side under the action of the pressure gradient. By monitoring the pressure in the low-pressure side, the gas permeability, gas permeability coefficient, gas diffusion coefficient and gas solubility coefficient of the tested sample can be obtained.
2. Isobaric method
1) Gas chromatography detection method: Use a sample to separate the gas permeable test chamber into a gas supply side and a gas permeation side. When the pressure on both sides of the sample is the same, the carrier gas and the test gas are continuously supplied to both sides at the same flow rate to ensure a continuous constant concentration difference on both sides of the sample. The test gas penetrates through the sample under the action of the concentration difference and is sent to the gas chromatography detector by the carrier gas, passing through the data processing device to obtain the tested sample.
2) Coulomb meter detection method: Use a sample to separate the breathable test chamber into a gas supply side and a gas permeation side. When the pressure on both sides of the sample is the same, the carrier gas and the test gas are continuously supplied to both sides at the same flow rate to ensure a continuous constant concentration difference is formed on both sides of the sample; the test gas penetrates through the sample under the action of the concentration difference and is sent to the Coulomb power sensor by the carrier gas.
The test gas that has penetrated the sample undergoes an electrochemical reaction with the Coulomb power sensor. The Coulomb power sensor converts the gas quantity into an electrical signal to obtain the gas permeability and gas permeability coefficient of the tested sample.

GB/T 7755.2-2019 Determination of air permeability of vulcanized rubber or thermoplastic rubber Part 2: Isobaric method
GB/T 7755.1-2018 Determination of air permeability of vulcanized rubber or thermoplastic rubber Part 1: Differential pressure method
ISO 2782-1 -2016 Determination of air permeability of vulcanized rubber or thermoplastic rubber Part 1: Differential pressure method
ISO 2782-2-2011 Determination of air permeability of vulcanized rubber or thermoplastic rubber Part 2: Isobaric method
BS ISO 2782-1 -2016 Determination of air permeability of vulcanized rubber or thermoplastic rubber Part 1: Differential pressure method
BS ISO 2782-2 -2012 Determination of air permeability of vulcanized rubber or thermoplastic rubber Part 2: Isobaric method
NF ISO 2782-1 -2016 Determination of air permeability of vulcanized rubber or thermoplastic rubber Part 1: Differential pressure method
NF ISO 2782-2 -2012 Determination of air permeability of vulcanized or thermoplastic rubbers Part 2: Isobaric method